1. Field of the Invention
Aspects of the present invention relate to an electrode assembly and a secondary battery including the same.
2. Description of the Related Art
Recently, the use of portable electronic devices has increased with the rapid development of communication and computer industries. Rechargeable secondary batteries are widely used as power sources of portable electronic devices. A secondary battery generally includes an electrode assembly including a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode and insulating the positive electrode and the negative electrode from each other.
One of important considerations in the secondary battery is to control occurrence of swelling during storage at a high temperature. In particular, when lithium titanate oxide (LTO) is contained as a negative electrode active material, an extent of swelling in a discharged state (0% state of charge (SOC)) is greater than that in a charged state (100% SOC). Sealing of the secondary battery may be broken due to the swelling, resulting in leakage of electrolyte or infiltration of moisture, thereby ultimately degrading the battery performance. Accordingly, the control of swelling of the secondary battery is an important issue to be considered.